It is only a shotgun barrel, which really is "Soft steel". If the holes are only 8-32 or less I would not be afraid to put the screws in. I don't know how equipped with machines you are, but I would then make a steel scope base and silver solder it on. I bore a slug to the tube diameter leaving plenty on the OD of the slug to work with. Machine the OD to take a Weaver base (The easiest to work with), split the slug and mount a scope on it to check position before soldering. You may have to take in to consideration the taper of the barrel and build it into the base.It is deceiving where the scope should sit on a single shot, so check the position before soldering. There is hardly any pressure at the chamber area. Just look at the construction of a shotgun shell. I have seen many shotgun tubes split like a banana peel pulled apart in the middle, but never seen a chamber area split.